Develop Reference

How to run background.js only on specific links?

I'm trying to write a chrome extension that closes tabs when they're loaded if their links contain specific words / strings. My intention was to solve that using the matches statement in the manifest.json. Unfortuantely this doesn't work. My manifest.json looks like this:
{
"manifest_version": 2,
"name": "Chrome Extension",
"version": "0.1",
"permissions": [
"tabs"
],
"content_scripts": [
{
"matches": [
"<all_urls>"
],
"js": ["content.js"]
}
],
"background": {
"matches": [
"https://www.google.de/",
"https://sghm.eu/iserv/login"
],
"scripts": ["background.js"],
"persistent": true
}
}
And my background.js like this:
chrome.tabs.onUpdated.addListener( function (tabId, changeInfo, tab) {
if (changeInfo.status == 'complete') {
console.log('background running');
chrome.tabs.remove(tabId, function() { });
}
})
In my opinion I've expressed clearly that the script only runs on google and sghm.eu, so why does it run on every loaded page?

Problems:
The "background" section can't have "matches" as you can see in the documentation. The background script runs in a separate hidden background page that's not related to tabs.
The content script declared in your manifest.json runs on all URLs. For the task you want to achieve you don't need a content script at all.
Solution consists of several steps:
Remove "content_scripts" section
Remove "matches" from "background" section
Switch to an event page script by specifying "persistent": false
Add "webNavigation" permission in manifest.json and use it to detect URL navigation.
background.js:
chrome.webNavigation.onCompleted.addListener(closeTab, {
url: [
{urlPrefix: 'https://www.google.de/'},
{urlPrefix: 'https://sghm.eu/iserv/login'},
]
});
function closeTab(e) {
if (!e.frameId) {
chrome.tabs.remove(e.tabId);
}
}

chrome extension: page loaded event and update url

I want to change the url of current tab in chrome and reload the page.
I tried this code but not work, any help here will be greatly appreciated.
background.js:
function updateUrl(){
chrome.tabs.getCurrent(function (tab) {
var tabUrl = encodeURIComponent(tab.url);
var myNewUrl = tabUrl + "some text";
chrome.tabs.update(tab.id, {url: myNewUrl});
})
}
chrome.tabs.onUpdated.addListener( function (tabId, changeInfo, tab) {
if (changeInfo.status == 'complete') {
updateUrl();
}
})
manifest.json:
{
"name": "test",
"version": "0.1",
"manifest_version": 2,
"permissions": [
"tabs",
"webNavigation",
"http://www.example.com/*"
],
"background": { "scripts": ["background.js"] },
"content_scripts":
[
{
"matches": ["http://www.example.com/*"],
"js": ["background.js", "jquery.js"]
}
]
}

From your manifest it looks like you're trying to include background.js as a content script and a background script. chrome.tabs isn't available in content scripts so this won't work.
Depending on your specific use case, if you want to append a specific URL you could use the chrome.webRequest API to achieve this.
background.js:
chrome.webRequest.onBeforeRequest.addListener(function (details) {
return {
redirectUrl: details.url + "some text"
}
}, {
urls: ["http://www.example.com/*"]
}, ["blocking"]);
manifest.js:
{
"name": "test",
"version": "0.1",
"manifest_version": 2,
"permissions": [
"webRequest",
"webRequestBlocking",
"http://www.example.com/*"
],
"background": {
"scripts": [
"background.js"
]
}
}
This will add "some text" to the end of every request the browser makes to "http://www.example.com/*"
If you do want to use a content script to do this, then you'll need to take a look at message passing. This will allow you to make a call to the background script (which can use chrome.tabs) from your content script. Once the message has been sent the background page could then update the tab.

chrome.tabs.getCurrent is used to get the tab that this script is being made from. It will return undefined if called from a non-tab context (for example: a background page or popup view).
Since you have got the tab inside chrome.tabs.onUpdated handler, you could directly use it without the need to retrieve it again.
function updateUrl(tabId, tabUrl){
var myNewUrl = encodeURIComponent(tabUrl) + "some text";
chrome.tabs.update(tabId, {url: myNewUrl});
}
chrome.tabs.onUpdated.addListener( function (tabId, changeInfo, tab) {
if (changeInfo.status == 'complete') {
updateUrl(tab.id, tab.url);
}
});
From you manifest.json, background.js are used for both background page and content scripts, that's a bad design though not the root cause for this question.
It would be better if you could divide the logic into two parts, content script used for manipulating current web page DOM and background page used for extension related things.

Which URLs are restricted to operate on with Chrome extensions? [duplicate]

I have created a Chrome extension that, as part of it's operation, opens a new tab with a specified url.
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
if( request.message === "open_new_tab" ) {
chrome.tabs.create({"url": request.url});
}
}
);
(Full code available on GitHub)
This works fine on tabs with webpages, but I cannot get it to work on empty tabs, for example: chrome://apps/ To clarify, if I have a tab open and it is on stackoverflow.com, then when I click on my extension button it opens a new tab loading a generated url. When I am on a new tab, or a tab where the url begins with chrome:// then the extension does not work.
What permissions do I need to include to allow the extension to open in ANY tab? Including new tabs and any chrome:// tab?
Manifest.json:
{
"manifest_version": 2,
"name": "MyMiniCity Checker",
"short_name": "MyMiniCity Checker",
"description": "Checks what your city needs most and redirects the browser accordingly.",
"version": "0.2",
"author":"Richard Parnaby-King",
"homepage_url": "https://github.com/richard-parnaby-king/MyMiniCity-Checker/",
"icons": {
"128": "icon-big.png"
},
"options_page": "options/options.html",
"browser_action": {
"default_icon": "icon.png"
},
"permissions": ["tabs","storage","http://*.myminicity.com/","http://*/*", "https://*/*"],
"background": {
"scripts": ["background.js"],
"persistent": false
},
"content_scripts": [ {
"matches": [ "http://*/*", "https://*/*"],
"js": [ "jquery-1.11.3.min.js" ]
}]
}
Background.js:
//When user clicks on button, run script
chrome.browserAction.onClicked.addListener(function(tab) {
chrome.tabs.executeScript(null, { file: "jquery-1.11.3.min.js" }, function() {
chrome.tabs.executeScript(null, { file: "contentscript.js" });
});
});
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
if( request.message === "open_new_tab" ) {
chrome.tabs.create({"url": request.url});
}
}
);
It appears as though the background.js file is not being executed. I suspect this to be a permissions. What permissions do I need in order to run this extension in every tab?

Well, this message is supposed to come from a content script you're trying to inject into the current tab.
The widest permission you can request is "<all_urls>", however, there are still URLs that are excluded from access.
You can only normally access http:, https:, file: and ftp: schemes.
file: scheme requires the user to manually approve the access in chrome://extensions/:
Chrome Web Store URLs are specifically blacklisted from access for security reasons. There is no override.
chrome:// URLs (also called WebUI) are excluded for security reasons. There is a manual override in the flags: chrome://flags/#extensions-on-chrome-urls, but you can never expect it to be there.
There is an exception to the above, chrome://favicon/ URLs are accessible if you declare the exact permission.
All in all, even with the widest permissions you cannot be sure you have access. Check for chrome.runtime.lastError in the callback of executeScript and fail gracefully.

As I was wanting this to run on EVERY page it meant I could not have the code in the content script. I moved all the code into the background script:
chrome.browserAction.onClicked.addListener(function(tab) {
//...
chrome.tabs.create({"url": newTabUrl});
//...
});
So when I click on my button the above code is called, using the enclosed jquery script.

Chrome extension inject js

I want to create a new chrome extension but it don't work.
I want to inject a js file into web page (all web page,not only one.If i push the chrome icon on google the script must execute,if i push the icon on facebook it must execute ect.)
this is background.js
chrome.browserAction.onClicked.addListener(function(tab) {
chrome.tabs.executeScript({
null,{file: "backgrounds.js"} });
});
this is backgrounds.js
document.body.innerHTML="display div elem with style and id";
this is manifest.json
{
"name": "MyExt",
"description": "an extension,what else?",
"version": "1.0",
"permissions": [
"activeTab"
],
"content_scripts": [
{
"matches": ["http://*/*"],
"js": ["background.js"]
}
],
"browser_action": {
"default_title": "myExt"
},
"manifest_version": 2
}
what i wrong?
I'm on windows 8.1 Update 1 with chrome last version

Your manifest is wrong: you should set background.js as your background script:
"background" : { "scripts" : [ "background.js" ] },
and remove the "content_scripts" section.
The "activeTab" permission means that you don't need to specify host permissions to inject in the current tab upon browser action click, so no other permissions are needed.
The tabId argument is optional, you can just drop it instead of passing null. And your invocation is wrong (you're wrapping two arguments in a single object). Here's the correct way:
chrome.browserAction.onClicked.addListener(function(tab) {
chrome.tabs.executeScript({file: "backgrounds.js"});
});

Chrome Extension - edit a text field

I'm trying to write my first Chrome extension. It would, when clicked, automatically fill the fields of an ID and password for my University's login page (which has its form's auto-fill disabled).
It's a very specific page.
I have a few problem.
I've searched Google and SO but couldn't find an explanation on how to change the value of a text field through Chrome. I know how to do this in HTML and JavaScript, however I couldn't get the proper input to modify its text.
I've also tried using jQuery using a few examples I've found, but no luck.
I have an HTML page (popup.html) which calls a JavaScript file.
I've also tried placing the JS in a content script
Here's the manifest.json:
{
"name": "My First Extension",
"version": "1.0",
"manifest_version": 2,
"description": "The first extension that I made.",
"browser_action": {
"default_icon": "icon.png",
"default_popup": "popup.html"
},
"permissions": [
"tabs", "http://*/*"
],
"content_scripts": [
{
"matches": ["http://*/*"],
"js": ["jquery-1.7.2.min.js","content.js"]
}
]
}
One of my attempt of popup.js (which gets called from popup.html) is:
chrome.tabs.getSelected(null, function(tab) {
console.log(document)
});
I've also tried placing this code inside the content.js. same result,
It prints to console, however it prints the popup.html content..
I've also tried directly (and from the above method) to access an element directly by document.getElementById() but still no luck..
So,
Can anyone tell me what I'm doing wrong?

You need to inject a JavaScript file to the page using the "web_accessible_resources" attribute. See here:
manifest.json
{
"name": "My First Extension",
"version": "1.0",
"manifest_version": 2,
"description": "The first extension that I made.",
"browser_action": {
"default_icon": "icon.png"
},
"permissions": [
"tabs", "http://*/*"
],
"content_scripts": [
{
"matches": ["http://*/*"],
"js": ["jquery-1.7.2.min.js","content.js"],
"run_at": "document_start"
}
],
"web_accessible_resources": ["inject.js"]
}
inject.js
(function () {
console.log('test');
}());
content.js
(function (chrome) {
var js = document.createElement('script');
js.type = 'text/javascript';
js.src = chrome.extension.getURL('inject.js');
document.getElementsByTagName('head')[0].appendChild(js);
}(chrome));
Then just put the JavaScript code you want to use in inject.js to manipulate the page. Be sure to change matches to only match your University's login page.
The reason this is the case is because Chrome extensions can run and operate on their own regardless of which website you're on. And they can continue to process as you switch pages. They're in their own sandboxed environment.

I think you should use a simple content script that is executed on the login page. You don't even need any browser action or popup for that.
Here's a manifest:
{
"name": "Fill my password",
"version": "1.0",
"manifest_version": 2,
"description": "Fills my password on University login page",
"content_scripts": [
{
"matches": ["http://www.myuniversity.edu/login.html"],
"js": ["content.js"]
}
]
}
And here's a content script:
// define your username and password
var myUsername = '...';
var myPassword = '...';
// find the fiends in your login form
var loginField = document.getElementById('...');
var passwordField = document.getElementById('...');
// fill in your username and password
loginField.value = myUsername;
passwordField.value = myPassword;
// if you want, you can even automaticaly submit the login form
var loginForm = document.getElementById('...');
loginForm.submit();

Possible workaround(chrome extension): Autocomplete = on, but it could not work with some forms.